There is no problem copying the master's thesis. The key is to use it. There is no problem with the arrangement of the master's thesis itself. If you like the master's thesis very much, you can save it after copying it, and save it in the form of a document in the computer. This is understandable, but copying a master's thesis into your own is definitely not acceptable. This is a kind of plagiarism and academic misconduct.

Papers can be referenced, but not copied and pasted in large quantities. Your usual papers are not so rigorous. It doesn't matter if you copy and paste, but if it's a graduation thesis, you need to check it again. Most colleges and universities require that the duplicate checking rate is less than 30% to be successful, and the duplicate checking rate standard for master's and doctoral dissertations is generally less than 20% to be qualified. The standard of doctoral graduation examination is the strictest, and it is generally required that the duplicate checking rate of graduation thesis is lower than 10% to pass the examination.